Dr Zifang Liu1,5, Dr Rupert Collins2, Dr Charles Baillie3, Dr Jennifer Freer2,4, Dr Ryan Saunders4, Dr Geraint Tarling4, Prof Stefano Mariani3,5, Prof Martin Genner2
1School of Biological Sciences, University of Bristol, Life Sciences Building, Bristol, UK, 2Ecosystems and Environment Research Centre, School of Environment & Life Sciences, University of Salford, UK, 3British Antarctic Survey, , UK, 4School of Biological & Environmental Sciences, Liverpool John Moores University, , UK, 5Guangdong University of Technology, Guangzhou, China
Biography:
Zifang Liu is a postdoctoral researcher in marine ecology, focusing on marine megafauna conservation. She is using eDNA-based methods to address the data deficiency on marine megafauna distribution, which arises from a lack of long-term observations and trawling data in developing countries.
Abstract:
Mesopelagic fish are known to be fundamental to the sustenance of the vulnerable and productive food webs in the Southern Ocean, but distributions and abundance can be challenging to quantify using survey trawls. Here we initially explored the capacity of environmental DNA metabarcoding to quantify the structure of mesopelagic fish assemblage of the Scotia Sea across a depth gradient from the surface to 850m. We then compared the eDNA-based results to trawls undertaken at the same locations and depths. Overall, using eDNA-based methods we identified a gradient in community structure with increasing depth, albeit less prominent than that observed in the trawl survey data. We also found evidence that across species and sampling locations, fish species abundance in the net survey was a predictor of eDNA read abundance. In addition, we explored broader patterns of fish in surface-collected samples, identifying the presence of multiple epipelagic and demersal fish species. Finally, we mapped the distribution of ten marine mammal species encountered as “molecular bycatch”. Collectively, these results indicate that eDNA-based methods may be useful for ecological assessments of fish stocks alongside conventional survey approaches, and may also be valuable for mapping distributions of pelagic marine mammal species in oceanic environments.